Flexible Pavement Design Simulator
Adjust the sliders below to see how traffic characteristics affect the required thickness of flexible pavement layers. Higher traffic volume, heavier axle loads, and longer design life all increase the stress on the pavement, requiring thicker layers (Surface, Base, Sub-base) to distribute the load and prevent premature failure.
2000 Axles/day
80 kN
15 Years
Sub-base Course
Base Course
Surface Course (Asphalt)
Surface: -- mm
Base: -- mm
Sub-base: -- mm
AIM
To determine the penetration value of given Bitumen.
THEORY
The consistency of bituminous material varies depending up on several factors such as constituents, temperature, etc. Determination of absolute viscosity of bituminous material is not so easy. Therefore, the consistencies of these materials are determined by indirect method. Penetration value is an indirect method of measurement of hardness or consistency of bituminous material. It is the vertical distance traversed or penetrated by the point of a standard needle into the bituminous material under specific conditions of load, time and temperature. This distance is measured in one tenth of a millimeter. Softer the bitumen greater will be the penetration. The penetration test is widely used for classifying the bitumen in to different grades. The BIS has standardised the penetration test equipment and the test procedure. It is not regarded as suitable for use in connection with the testing of road tar because of the high surface tension exhibited by these materials and the fact that they contain relatively large amount of free carbon.
APPARATUS
a) Container - A metal or glass cylindrical, flat bottom container of essentially the following dimensions shall be used:
For penetrations below 225:
Diameter, mm - 55
Internal depth, mm - 35
For penetrations between 225 and 350:
Diameter, mm - 70
Internal depth, mm - 45
b) Needle- A straight highly polished cylindrical stainless steel rod. The needle is provided with a shank approximately 3 mm in diameter into which it is immovably fixed. The taper shall be symmetrical and the point shall be 'blunted' by grinding to a truncated cone.
c) Water Bath - A water bath preferably with a thermostat maintained at 25.0 ± 0.1 °C (containing not less than 10 litres of water. The sample being
immersed to a depth of not less than 100 mm from the top and supported on a perforated shelf not less than 50 mm from the bottom of the bath.
d) Transfer Dish - A small dish or tray, provided with some means which ensure a firm bearing and prevent the rocking of the container, and of such capacity as will ensure complete immersion of the container during the test.
e) Thermometer – a thermometer of range 0 to 44 °C.
f) Time device- For hand operated penetrometers, a timer device or stop watch, accurate to 0.1 second.
PROCEDURE
1. The bitumen is heated to a pouring consistency, about 75 to 100°C above the temperature at which bitumen softens. The sample is thoroughly stirred to make it homogeneous and free from air bubbles and water.
2. The sample is poured into the container of 35 mm depth (to a depth at least 10 mm more than the expected penetration).
3. The sample containers are placed on the transfer tray and cooled in atmosphere at temperature between 15 to 30 °C for 60 to 90 minutes.
4. Transfer the tray with containers is placed in the thermostatically controlled water bath maintained at a temperature of 25.0±0.1 °C for a period of 60 to 90 minutes (for testing bitumen with penetration value between 225 and 350, the container of depth 45 mm and diameter 70mm is used and the cooling period in atmosphere and in water bath is 90 to 120 minutes each.)
5. The transfer tray with sample container and water is removed from the water bath and placed under the needle of penetrometer.
6. Using adjusting screw, the needle assembly is lowered and the tip of the needle is made to just touch the top surface of bitumen sample and the needle assembly is clamped in this position.
7. The contact of the tipoff the needle is checked using the mirror placed on the rear of the needle. The initial reading of penetrometer dial is either adjusted to zero or the initial reading is taken before releasing the needle.
8. The needle is released exactly for a period of5.0 seconds by pressing the knob and the final reading is taken on the dial.
9. The needle assembly is then raised and the penetration needle is removed and replaced by a clean, dry needle.
10. At least three such measurements are made on this sample at testing distance of not less than 10 mm apart. After each test the needle is designated and cleaned with benzene and carefully dried. The test is repeated on the sample in the other containers, after keeping in the water bath maintained at a temperature of 25°C.
OBSERVATION AND CALCULATIONS
Period of curing in atmosphere =
Period of curing in water bath =
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Penetrometer Dial Reading |
Test 1 |
Test 2 |
Test 3 |
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Initial |
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Final |
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Penetration Value |
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Mean penetration value =
RESULT
Penetration value of bitumen =
INFERENCE FROM TEST
Penetration test is most commonly adopted test in bitumen to determine the grade of material in terms of its hardness because of its simplicity. The penetration grades of bitumen are generally denoted as 80/100, 60/70, or 30/40 grade bitumen. 80/100 bitumen denote that the penetration value of the binder ranges between 80 and 100. The penetration value of various type of bitumen used in pavement construction in this country ranges between 20 to 225. The appropriate grade of bitumen binder to be used for road construction work is decided depending upon the climatic condition of the project site, the type of construction / specification and the pavement layer (base course binder / course surface / course). Harder grade of bitumen binder with lower penetration value is generally used in warm region. In cooler region bitumen with higher penetration value is generally used. However, binders which become very stiff at low temperature are not preferred for road construction in region with cold weather.
Reference Code : IS:8887-2004
AIM
To test the Bitumen Emulsion for coagulation at low temperature to ensure the homogeneity and stability, if exposed or stored at sub-zero temperature.
APPARATUS
a) Boiling tube
b) Water bath
c) Refrigerator
d) Glass rod
e) 600-micron IS sieve
f) Beakers -Two, 600 ml capacity
PROCEDURE
1. Sieve bitumen emulsion through 600-micron IS sieve
2. 20 ml of previously sieved homogenous bitumen emulsion is transferred in to a boiling tube
3. The temperature of this boiling tube is brought to 30°C by plunging the tube into water bath previously set at 30°C with gentle stirring by a glass rod.
4. Once the temperature of bitumen emulsion is constant at 30°C, the tube is plunged into ice bath or refrigerator previously set to 0°C with slow stirring by rod.
5. Once the temperature of emulsion reaches 0°C, discontinue stirring and the tube is transferred into another beaker with a freezing mixture at a temperature of -3 to -4°C for 30 minutes.
6. Finally, the tube is removed from refrigerator and brought to room temperature without any disturbance
7. The emulsion is filtered through 600 micron IS sieve and sieve is washed with distilled water and checked for residual bitumen coagulation.
FINDING FROM TEST
The emulsion has passed the test, if there is no coagulation.
SPECIFICATION DETAILS
As per IS 8887:2004, coagulation at Low Temperature should be NIL
Its a technique used in Road Construction (Flexible Pavement).
Does not pollute the environment, during the process of paving roads.
What is Cold Mix?
Does not pollute the environment, during the process of paving roads.
What is Cold Mix?
It is a mixture of Bitumen Emulsion and Aggregate at ambient temperature, to mix bitumen emulsion with aggregate there is no need of heating process. The bitumen emulsion remains liquid at room temperature.
What is Bitumen Emulsion?
An emulsion is a mixture of two or more liquid which are non-mixable. When bitumen is suspended with water in the presence of emulsifiers it forms bitumen emulsion. The emulsifiers are divided into Anionic Emulsifiers and Cationic Emulsifiers.
Types of Emulsion
1.Anionic Emulsion
2.Cationic Emulsion
3.Non Ionic Emulsion
Where Cold Mix Technology can be used?
1. It is useful in areas where there is a longer distance between job site and batching plant.
2. It can be used in locations that have a very low and moderate temperature (<40 degree C)
Advantages of Cold Mix Technology
1.There is no option for heating the bitumen mix (no heating process).
2.It is environment friendly and does not create pollution (no pollution).
3.Does not requires costly equipment and high workability.
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| Used for Cold Mix process |
4.Option to engage Unskilled Labours.
5.Work can be carried in almost all weather season ie. wet and humid climate.
6.It increase the speed of work activity
Introduction Road Safety Audit (RSA)
It is a systematic formal road safety assessment of a road scheme carried by an independent, qualified auditor who report on the projects accident potential for all kinds of road users. RSA is not a mean to rank or rate a project, it check the compliance with standards. Also it does not attempt to redesign a project, only gives recommendations or finding that should be considered.
Benefits of Road Safety Audit
- Provide safety beyond established standards
- Identify additional improvement that can be incorporated into the projects
- Create consistency among all projects
- Invite interdisciplinary input
- Enhance the quality of field reviews
- Provide learning experiences for the audit team and design team members
- Provide feedback to highway designers that they can apply to other projects
- To ensure that a high quality is maintained throughout a project life cycle
Key Elements
- It is a formal examination with a structured process
- It is conducted independently by professionals who are not involved in the projects
- It consist of a team of qualified professionals representing appropriate discipline
- It focus only on safety issues
Traffic Calming is also called Speed management by design, speed of motor vehicles are increasing rapidly which result in increasing road accidents. when speed is reduced naturally the accident is also reduced. Traffic calming is an effort made to manage or reduce speed by engineering measures.
Aim of Traffic Calming
- To reduce traffic volume and speed on local streets
- Restricting the entry of heavy vehicles on local streets
- Reduce accidents and noise pollution
- Providing a safer environment for road users
- Developing appropriate driving behavior
Techniques of Traffic Calming
1. Advanced warninga.Visual Warning
2. Restricted Techniques
a.Staggering of lanes
b.Narrow lanes
c.Reducing Pedestrian crossing distance
A Queue is formed when the demand exceeds the capacity for a time period or arrival time is less than service time at a specific location. The queue can be stopping queue or moving queue. Examples in Transportation Engineering can be intersection , toll plazas, etc,.
Inputs for Queuing System Analysis
This Application is developed for a Single and Multiple Service Channel (M/M/N System where arrival and service time are Random) application can serve maximum of 10 Channels, this can be used for analyzing Bus Terminals with number of platforms, Toll Plaza, Parking lot etc.,
- Mean Arrival Value
- Arrival Distribution
- Mean Service Value
- Service Distribution
- Queue Discipline
This Application is developed for a Single and Multiple Service Channel (M/M/N System where arrival and service time are Random) application can serve maximum of 10 Channels, this can be used for analyzing Bus Terminals with number of platforms, Toll Plaza, Parking lot etc.,
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| Toll Plaza |
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| Bus Terminal Portable Version Compatible with all version of Windows  |
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